<p>Group subscriptions are similar to groups but created and managed by another 
user. To subscribe to a group, use the Group - Subscribe to Group menu item. If 
any subscribable groups are available, they will appear in the popup window.</p>

<p>To unsubscribe from a group, click on the group on the left side, and then 
click on the Group - Unsubscribe from Selected Group menu item</p>
